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{ "id": 2217290, "url": "http://patchwork.ozlabs.org/api/covers/2217290/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/cover/20260327205457.604224-1-surenb@google.com/", "project": { "id": 2, "url": "http://patchwork.ozlabs.org/api/projects/2/?format=api", "name": "Linux PPC development", "link_name": "linuxppc-dev", "list_id": "linuxppc-dev.lists.ozlabs.org", "list_email": "linuxppc-dev@lists.ozlabs.org", "web_url": "https://github.com/linuxppc/wiki/wiki", "scm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git", "webscm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/", "list_archive_url_format": "https://lore.kernel.org/linuxppc-dev/{}/", "commit_url_format": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}" }, "msgid": "<20260327205457.604224-1-surenb@google.com>", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/20260327205457.604224-1-surenb@google.com/", "date": "2026-03-27T20:54:51", "name": "[v6,0/6] Use killable vma write locking in most places", "submitter": { "id": 74729, "url": "http://patchwork.ozlabs.org/api/people/74729/?format=api", "name": "Suren Baghdasaryan", "email": "surenb@google.com" }, "mbox": "http://patchwork.ozlabs.org/project/linuxppc-dev/cover/20260327205457.604224-1-surenb@google.com/mbox/", "series": [ { "id": 497828, "url": "http://patchwork.ozlabs.org/api/series/497828/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=497828", "date": "2026-03-27T20:54:51", "name": "Use killable vma write locking in most places", "version": 6, "mbox": "http://patchwork.ozlabs.org/series/497828/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2217290/comments/", "headers": { "Return-Path": "\n <linuxppc-dev+bounces-18938-incoming=patchwork.ozlabs.org@lists.ozlabs.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "linuxppc-dev@lists.ozlabs.org" ], "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256\n header.s=20251104 header.b=dTU8G2gY;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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Fri, 27\n Mar 2026 13:55:01 -0700 (PDT)", "Date": "Fri, 27 Mar 2026 13:54:51 -0700", "X-Mailing-List": "linuxppc-dev@lists.ozlabs.org", "List-Id": "<linuxppc-dev.lists.ozlabs.org>", "List-Help": "<mailto:linuxppc-dev+help@lists.ozlabs.org>", "List-Owner": "<mailto:linuxppc-dev+owner@lists.ozlabs.org>", "List-Post": "<mailto:linuxppc-dev@lists.ozlabs.org>", "List-Archive": "<https://lore.kernel.org/linuxppc-dev/>,\n <https://lists.ozlabs.org/pipermail/linuxppc-dev/>", "List-Subscribe": "<mailto:linuxppc-dev+subscribe@lists.ozlabs.org>,\n <mailto:linuxppc-dev+subscribe-digest@lists.ozlabs.org>,\n <mailto:linuxppc-dev+subscribe-nomail@lists.ozlabs.org>", "List-Unsubscribe": "<mailto:linuxppc-dev+unsubscribe@lists.ozlabs.org>", "Precedence": "list", "Mime-Version": "1.0", "X-Mailer": "git-send-email 2.53.0.1018.g2bb0e51243-goog", "Message-ID": "<20260327205457.604224-1-surenb@google.com>", "Subject": "[PATCH v6 0/6] Use killable vma write locking in most places", "From": "Suren Baghdasaryan <surenb@google.com>", "To": "akpm@linux-foundation.org", "Cc": "willy@infradead.org, david@kernel.org, ziy@nvidia.com,\n\tmatthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com,\n\tbyungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com,\n\tapopple@nvidia.com, ljs@kernel.org, baolin.wang@linux.alibaba.com,\n\tLiam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com,\n\tdev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, vbabka@suse.cz,\n\tjannh@google.com, rppt@kernel.org, mhocko@suse.com, pfalcato@suse.de,\n\tkees@kernel.org, maddy@linux.ibm.com, npiggin@gmail.com, mpe@ellerman.id.au,\n\tchleroy@kernel.org, borntraeger@linux.ibm.com, frankja@linux.ibm.com,\n\timbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com,\n\tagordeev@linux.ibm.com, svens@linux.ibm.com, gerald.schaefer@linux.ibm.com,\n\tlinux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, surenb@google.com", "Content-Type": "text/plain; charset=\"UTF-8\"", "X-Spam-Status": "No, score=-7.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED,\n\tDKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,\n\tUSER_IN_DEF_DKIM_WL autolearn=disabled version=4.0.1 OzLabs 8", "X-Spam-Checker-Version": "SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org" }, "content": "Now that we have vma_start_write_killable() we can replace most of the\nvma_start_write() calls with it, improving reaction time to the kill\nsignal.\n\nThere are several places which are left untouched by this patchset:\n\n1. free_pgtables() because function should free page tables even if a\nfatal signal is pending.\n\n2. userfaultd code, where some paths calling vma_start_write() can\nhandle EINTR and some can't without a deeper code refactoring.\n\n3. mpol_rebind_mm() which is used by cpusset controller for migrations\nand operates on a remote mm. Incomplete operations here would result\nin an inconsistent cgroup state.\n\n4. vm_flags_{set|mod|clear} require refactoring that involves moving\nvma_start_write() out of these functions and replacing it with\nvma_assert_write_locked(), then callers of these functions should\nlock the vma themselves using vma_start_write_killable() whenever\npossible.\n\nChanges since v5 [1]:\n- Added Reviewed-by for unchanged patches, per Lorenzo Stoakes\n\nPatch#2:\n- Fixed locked_vm counter if mlock_vma_pages_range() fails in\nmlock_fixup(), per Sashiko\n- Avoid VMA re-locking in madvise_update_vma(), mprotect_fixup() and\nmseal_apply() when vma_modify_XXX creates a new VMA as it will already be\nlocked. This prevents the possibility of incomplete operation if signal\nhappens after a successful vma_modify_XXX modified the vma tree,\nper Sashiko\n- Removed obsolete comment in madvise_update_vma() and mprotect_fixup()\n\nPatch#4:\n- Added clarifying comment for vma_start_write_killable() when locking a\ndetached VMA\n- Override VMA_MERGE_NOMERGE in vma_expand() to prevent callers from\nfalling back to a new VMA allocation, per Sashiko\n- Added a note in the changelog about temporary workaround of using\nENOMEM to propagate the error in vma_merge_existing_range() and\nvma_expand()\n\nPatch#5:\n- Added fatal_signal_pending() check in do_mbind() to detect\nqueue_pages_range() failures due to a pendig fatal signal, per Sashiko\n\n[1] https://lore.kernel.org/all/20260326080836.695207-1-surenb@google.com/\n\nSuren Baghdasaryan (6):\n mm/vma: cleanup error handling path in vma_expand()\n mm: use vma_start_write_killable() in mm syscalls\n mm/khugepaged: use vma_start_write_killable() in collapse_huge_page()\n mm/vma: use vma_start_write_killable() in vma operations\n mm: use vma_start_write_killable() in process_vma_walk_lock()\n KVM: PPC: use vma_start_write_killable() in\n kvmppc_memslot_page_merge()\n\n arch/powerpc/kvm/book3s_hv_uvmem.c | 5 +-\n fs/proc/task_mmu.c | 12 +--\n mm/khugepaged.c | 5 +-\n mm/madvise.c | 13 ++-\n mm/memory.c | 2 +\n mm/mempolicy.c | 21 +++-\n mm/mlock.c | 30 ++++--\n mm/mprotect.c | 25 +++--\n mm/mremap.c | 8 +-\n mm/mseal.c | 24 ++++-\n mm/pagewalk.c | 22 ++--\n mm/vma.c | 162 ++++++++++++++++++++++-------\n mm/vma_exec.c | 6 +-\n 13 files changed, 251 insertions(+), 84 deletions(-)\n\n\nbase-commit: e53c9040ab1b738dd2c83b57558f141902caaf4f" }